Each side of a metal plate is illuminated by light of different wavelengths. The left side is illuminated by light with λ0 = 500 nm and the

Question

Each side of a metal plate is illuminated by light of different wavelengths. The left side is illuminated by light with λ0 = 500 nm and the right side by light of unknown λ. Two electrodes A and B provide the stopping potential for the ejected electrons. If the voltage across AB is VAB=1.2775 V, what is the unknown λ?

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3 years 2021-08-12T13:22:36+00:00 1 Answers 5 views 0

The  wavelength is

Explanation:

From the question we are told that

The  wavelength of the left light is

The  voltage across A  and  B is

Let the stopping potential  at A  be and the electric potential at B  be

The voltage across A and B is mathematically represented as

Now  According to Einstein’s photoelectric equation the stopping potential at A for the ejected electron from the left side  in terms of electron volt is mathematically represented as

Where  W is the work function of the metal

h is the Planck constant with values

c  is the speed of light with value

And  the stopping potential at B for the ejected electron from the right side  in terms of electron volt is mathematically represented as

So

=>

=>

=>

=>

Where e is the charge on an electron with the value

=>

=>

=>

=>